Lecture 1 - Introduction Flashcards
What is microbiology?
the study of small organisms called microorganisms or microbes that are too small to be seen with the naked eye
what are microbes?
small organisms that are too small to be seen with the naked eye
what are examples of microbes we come across?
covid 19 virus, RSV virus, yeast, mold, yogurt, kimchi
all organisms can be divided into what 3 domains of life?
bacteria
archaea
eukarya
all organisms are made up of cells, what is it called when theres 1 cell and more than 1 cell?
1 cell = unicellular
>1 cell = multicellular
the bacteria and archaea domain contains what organisms? are they multicellular or unicellular?
prokaryotes with prokaryotic cells; unicellular
what are the organisms under the Eukarya domain? are they unicellular or multicellular?
eukaryotes with eukaryotic cells; they are both unicellular and multicellular
T/F: microbes are present in all 3 domains of life
TRUE
in the bacteria domain, what type of cells are present?
prokaryotic cells and they are unicellular
in the archaea domain, what type of cells are present?
prokaryotic cells and they are unicellular
in the eukarya domain, what type of cells are present?
eukaryotic cells and they are uni or multicellular
all organisms are made up of cells, what is it called when theres 1 cell and more than 1 cell?
1 cell = unicellular
>1 cell = multicellular
what are the 4 kingdoms under the eukarya domain?
- The protists kingdom
- Plantae kingdom
- Fungi kingdom
- Animalia kingdom
what is contained in the protists kingdom?
a. protozoa (unicellular)
b. algae (uni or multicellular)
what is contained in the fungi kingdom?
a. yeast (unicellular)
b. mold (multicellular)
what is contained in the animal kingdom?
a. helminths (multicellular)
do prokaryotes have a nucleus?
no, they have no compartments and their DNA is naked. like an empty office
do eukaryotes have a nucleus?
yes, they have a nucleus and compartments. there is DNA within the nucleus. like an office w/ cubicles
are viruses microbes?
yes
do viruses belong to a domain?
NO
where do viruses belong?
to the acellular infection agents
what are the two microbial categories?
- Living: with organisms
- Non-living: with acellular infectious agents
How is an acellular infectious agent different from an organism? Give an example of
each.
Acellular infectious agents are different from an organism because they are non-living and they don’t have a typical cell structure. An example of an acellular infectious agent is a virus. An example of an organism is algae.
what is within the non-living acellular infectious agents category?
viruses, viroids, and prions
how many micrometers (um) can we see with the naked eye?
100-200 um (micrometers)
how small is a bacteria?
1 um (micrometer) which is 1 meter divided by 1 million
how small is a virus?
20-200 nanometers (nm), which is when we divide a micrometer by 1 million again
how small is a eukaryote?
5-50 um
how small is a prokaryote?
0.3-2 um
T/F: most microbes can’t be seen with the naked eye except for one exception that was recently discovered
True
what technique do we use to name microbes?
binomial nomenclature
what is the binomial nomenclature?
the genus + the species AND it is italicized
what is an example of naming a microbe?
Escherichia coli or E. coli (italicized)
do we follow this naming system for acellular infectious agents?
no, we do not. for example, HIV
where are microbes?
everywhere (ubiquitous) - in soil, air, water, organisms, etc.
what is spontaneous generation?
that living things can arise from non-living matter via a “vital force”
what did francesco redi provide evidence against?
in 1668 he provided evidence against spontaneous generation. people believed his theory for microorganisms but no microorganisms
what was redi’s experiment?
he had a piece of meat in an unsealed flask, and that created living things.
he had a sealed flask with the meat, and no living things arises.
then he had a flask covered with gauze to allow air to come in, and again no living things arises.
did john needham provide evidence in support of spontaneous generation?
yes, he did in 1749. He did so by briefly boiling broth to kill all organisms and sealed the north flask to allow for gas exchange, but he still observed the spontaneous growth of organisms.
how did lazarro spallanzani provide evidence against spontaneous generation?
in 1776 he provided evidence against it by heating broth longer to kill all organisms, and sealed the flask for no gas exchange, and he did not observe spontaneous generation. so no growth of organisms
what did he say about air carrying microbes?
he said that air carries microbes into the flask which multiply to make more microbes. people said that he boiled too much to destroy the “vital force” and sealed too tightly which kept away the “vital force”
what did Louis Pasteur provide in evidence against spontaneous generation?
he kept the “swan-necked” flasks upright and there was no microbial growth despite being open to air. when the flask was titled, dust from the bend in the neck seeped back into the flask and made there be microbial growth, so boiling did not kill the vital force.
How did Pasteur disprove spontaneous generation? Explain the scientific
process – hypothesis, prediction, experiment, and conclusion.
Pasteur disproved it by using a swan-necked flask and he saw no microbial growth. This is where biogenesis came from, which is when living things arise from living things. He hypothesized that spontaneous generation wasn’t true. His prediction was that if he used the swan-necked flask and kept them upright, no microbial growth would appear despite being open to the air. And his experiment proved his prediction right. When the flask was titled, dust from the bend in the neck seeped back into the flask and created microbial growth. So is conclusion was that boiling did not kill the vital force.
Louis Pasteur came up with biogenesis, what is that?
that living things only arise from living things
who was the first person to build a microscope?
The first person to build a microscope was Robert Hooke in 1665.
who was the first person to observe microbes?
The first person to observe microbes was Antonie Van Leeuwenhoek in 1676.
where are bacteria present?
soil, water, air, organisms
what is a disease?
a noticeable impairment in body function
what is an infectious disease?
caused by a microbe (it invades, reproduces, and causes damage)
what is a pathogen?
a microbe causing disease
some bacteria are pathogens, what are examples?
E. coli, Vibrio cholerae
what are reasons for bacteria causing harm?
- Location (if it is in the wrong place; example E. coli being in the urinary tract instead of the intestines. this causes diarrhea and UTIs)
- Types or strains. (Some strains can produce toxins)
which of the 3 domains are the most ecologically diverse?
Archaea
what environments can archaea be present?
-Moderate environments (soil, ocean)
-Extreme environments: extremophiles
what are the different archaea present in extreme environments?
-Psychrophiles: cold-loving (Antarctica)
-Hyperthermophiles: superheat loving (hot springs, hydrothermal vents)
-Halophiles: salt-loving (Dead sea)
-Acidophiles: acid-loving (acid mines)
-Methanogens: make natural gas; anaerobic (swamps, intestines)
do archaea have pathogens?
no, they don’t cause any disease
Protists include animal-like unicellular eukaryotes called ___?
Protozoa
are protozoa consumers?
yes, they eat other organisms as they cannot make their own food
are protozoa motile?
yes, they can move around and are classified based on how they move (amoebas, flagellates, ciliates, sporozoans)
Protozoa include parasites, which are?
they live in or on host causing damage like Giardia lamblia (giardiasis, diarrhea) and Plasmodium falciparum (Malaria)
Protists also include plant-like unicellular or multicellular eukaryotes called ___?
algae
algae are photosynthetic, which is?
when they make their own food using sunlight, carbon dioxide, and water. they have pigments to absorb light
what are the different types of algae?
green, red, brown, golden
do algae have pathogens?
No
are algae toxigenic?
yes, they produce toxins that can cause disease upon ingestion. they can make toxins, not diseases.
where does agar come from?
algae
are fungi consumers?
yes, they depend on other organisms for food as they cannot make their own
are fungi motile?
no, they are non-motile
do some fungi cause diseases?
yes, some cause diseases called mycoses
what are examples of mycoses?
-Aspergillus: Aspergillosis
-Coccidiosis: Valley fever
myco means?
fungi
T/F: usually these diseases don’t affect healthy people
True
what are helminths?
multicellular eukaryotic animals, they look like worms
helminths have parasites, that do what?
they live in a host causing damage
are some parasites non microscopic?
yes, some can be seen w/ the naked eye
how are parasites passed from one to another?
they are passed from one person to another through eggs or larvae, which are microscopic
T/F: The microscopic larvae and eggs are the harmful part bc it transmits the disease
True
What are examples of parasitic diseases?
-Ascaris lumbricoides: ascariasis (roundworm)
-Taenia solium: taeniasis (tapeworm)
what are viruses?
they have a simple structure consisting of DNA or RNA surrounded by a proteins coat
do viruses have a cell structure?
no, they have DNA or RNA
viruses have obligate intracellular pathogens, what is that?
obligate intracellular pathogens that use the machinery and nutrients of host cells to replicate. (meaning they have to go in another cell to multiply)
T/F: usually, all cells have DNA in their genome. Viruses can have both DNA or RNA
True
what are viroids?
they are a simple structure consisting of only RNA
viroids also have obligate intracellular pathogens, which are?
they use the machinery and nutrients of host cells to replicate
do viroids cause human disease?
NO, they only cause plant disease
what are prions?
they are simple structures consisting of only protein
prions are infectious proteins, which are?
they are misfolded versions of normal cellular proteins that cause the normal versions to misfold and aggregate causing disease
what is an example of a disease caused by prions?
mad cow disease
most microbes affect us in a neutral way, do they harm us and help us too though?
yes
Robert Hooke did what?
in 1665 built the first compound microscope, w/ a magnification of 30x. He observed nematodes, mites, molds, etc. He coined the term “cells”
what did Antonie Van Leeuwenhoek do?
in 1676 he built a single lens microscope with a magnifaction of 300x. He observed rotten breath, blood, semen, lake water. etc.
Antonie Van Leeuwenhoek was the first to see what?
Bacteria and protozoa, which he described as little “animalcules”
who was the father of microbiology?
Antonie Van Leeuwenhoek
how old is the earth?
about 4.5 billion years old
when did the first living cell arise?
about 3.5 billion years ago
all life arose from what common ancestral cell?
from this common prokaryotic ancestral cell(s)
would we survive without microbes?
No, we would not
what is a human microbiome?
a group of microbes that live in/on us (our skin, mucus, GI tract, everywhere)
T/F: there are more microbial cells than human cells
True
In what ways are microbes beneficial to us?
They keep harmful microbes out, they aid in digestion, they promote immune system development
what two things contain nitrogen?
nucleic acid and protein
what organism can take nitrogen from the air?
bacteria and archaea, so that plants can have that nitrogen
Microbes recycle chemicals in the environment and decompose dead organisms and return them to the soil, what happens after?
then, photosynthetic microbes release oxygen into the air and the nitrogen-fixing microbes convert nitrogen gas in the air into a form that can be used by all other organisms to make proteins, nucleic acid, etc.
how are microbes used in food production?
microbes are used to make fermented food products like bread, beer, yogurt, cheese, buttermilk, kimchi, etc.
what are probiotics?
live beneficial microbes in food
what is bioremediation and how do microbes assist in that?
microbes can be used to clean up environmental pollutants like wastewater, toxic chemicals, oil spills, etc.
how do microbes assist in biotechnology?
they are used to make useful products like insulin, antibiotics, biofuel, etc. we also use microbes to study basic cellular processes in labs bc they are easier, cheaper, and faster to grow (ex: how cells divide, how cells copy DNA, etc)
microbes cause disease in what ways?
Vibrio cholera causes the digestive disease cholera. Mycobacterium tuberculosis causes respiratory disease tuberculosis.
SARS-CoV-2 belong to which domain of life?
None, because it is an acellular infectious agent.
A patient is showing the symptoms of a sore throat, a rash on the face and neck, and white spots on the back of the throat and tonsils. The nurse practitioner suspects that the patient has strep throat, but it could be a viral infection. Why is it important for the NP to know whether it is bacterial or viral infection before prescribing treatment?
It is important to know who caused the infection because the treatment depends on the identity of the pathogen. Antibiotics are used to treat bacterial infections, but they are ineffective against viruses. Viral infections usually self-resolve or are treated with antivirals.
A microbiologist obtained two biological samples: one of a virus, and one of a viroid. The labels came off during a move from one lab to the next, however. The scientist felt she could distinguish between the two samples by analyzing for the presence of a single type of molecule. What type of molecule would she be looking for to differentiate between the two?
Protein
Are antibiotics affective for viruses?
no
Are antibiotics affective for viruses?
No
Our bodies contain:
bacterial cell, prokaryotic cell, eukaryotic cell, archaea cells
what is one way E. coli is good for us?
E. coli is a part of the normal microflora of our large intestine (colon), where it helps in digestion, produces vitamins, and protects us from harmful microbes.
what is one way E. coli is bad for us?
E. coli can cause gastrointestinal and urinary tract infections.
Explain how the same bacterium can be “good” and “bad”.
While E. coli in the colon is beneficial to us, the same E. coli is harmful if it enters into the wrong location like the bladder causing a urinary tract infection (UTI)
While some types or strains of E. coli are beneficial, others are harmful or pathogenic because they possess extra genes coding for components like toxins.
Give one example of a pathogenic E. coli strain.
STEC - Shiga toxin-producing E. coli e.g. E. coli O157:H7. This pathogen is a part of the normal microflora of cattle. It is transmitted to humans primarily through the consumption of contaminated foods, such as raw or undercooked ground meat products and raw milk. Fecal contamination of water and other foods can also lead to infection.
In your own words, explain 2 ways in which microbes are essential for our lives.
2 ways in which microbes are essential for our lives are that they expose our body to certain bacteria which promote our immune system development, and there are certain microbes called probiotics that aid in digestion.
